On Sunday, the seven-day national average of new daily cases climbed past 214,000, an 83 percent jump over the past 14 days. Deaths also increased by 3 percent during that time, to a seven-day average of 1,328, according to a New York Times database.
Hospitalizations are up, too, although not as much as cases. More than 71,000 Americans are hospitalized with Covid-19, 8 percent higher than two weeks ago but still well below previous peaks.
In New York, Mayor Bill de Blasio on Monday implemented what he cast as the most sweeping vaccine mandate for private businesses in the nation. All employers in New York City now have to verify that their on-site workers have received at least one dose of a vaccine.
In Puerto Rico, new travel guidelines went into effect, requiring all passengers arriving on domestic flights to show a negative Covid test upon arrival or risk a fine. In Massachusetts, where Gov. Charlie Baker has activated the National Guard, 300 members were sent on Monday to acute-care hospitals and ambulance service providers.
In a conference call with governors on Monday, President Biden spoke of cooperation at various levels of government. Asa Hutchinson, the Republican governor of Arkansas, praised the president’s plan to give away 500 million rapid at-home tests, but said that federal efforts to stanch the infections must yield to state remedies.
“Look, there is no federal solution,” Mr. Biden replied. “This gets solved at the state level.”
“Ultimately it gets down to where the rubber meets the road, and that’s where the patient is in need of help or preventing the need for help,” he added.
On Monday, some business owners said the new C.D.C. guidance was helpful in addressing staffing shortages, as waves of workers fall sick. But they said that it still left employers and their workers with the challenge of determining how long people should isolate on a case-by-case basis.